1953 Power Steering issues - post pump rebuild - RESOLVED!

[Tye_Cowan]

Power Steering operated great, with the exception of a leaking front seal.

Rebuild kit purchased (overkill), complete teardown (with pics taken at each step), "O" rings replaced, vanes inspected and in place, front seal replaced (now I know I could have done this without the complete rebuild), tank seals replaced, tank seal spacers manufactured and installed, all reassembled and installed.  NO LEAKS!

But No Power Assist either.   

Double checked everything I could think of including the rotation direction marked on the pump.  Drained the pump, dismantled it, cleaned each piece (*), reinspected, re-verified assembly against the original photos, reassembled, reinstalled, and achieved the same results.  No Leak.  No Noise.  No Assist.

(*)The only thing that has me troubled is the 3M Gasket Sealer that was used on the tank gaskets.  Some oozed into the system during the first assembly.

Questions:

• Could some of the 3M goo have clogged or seized a critical valve or port?
• What happens if the pressure relief valve sticks?
• Are there any adjustments to be made on the pressure relief valve?
• If the "O" rings weren't seated properly, wouldn't it be leaking?

Anyone willing to help build a complete fault tree analysis?   

A friend suggested I start the engine, and crack open the high pressure fitting to see if it is under pressure, if it is, then the trouble is in the steering box.  I know "the book" says she should be putting out 700psi minimum.  But if she's putting out only 500psi, wouldn't the loose fitting still spray violently?  What is done to increase the output pressure?

Tonight, I'll be going to the parts store to create the pressure test kit.

All ideas and suggestions will be appreciated.

[savemy67]

Hello T M Cowan,

I am assuming the book you refer to is a '53 shop manual.  If the book says pump output pressure should be 700 PSI, I would speculate that if the pump produced 500 PSI, you would get some assist, not no assist.  So your friend's suggestion to crack the high pressure side will at least determine if the pump is producing pressure.  I do not have a '53 shop manual, but it may have a diagnostic "tree" - later manuals do.

For your pressure test kit - are you going to plumb a high-pressure gauge into the line?  Has the system been properly bled?

Christopher Winter

[Tye_Cowan]

You are correct.  I am using the 52/53 Caddilac Shop manual.  On my first attempt, I followed the instructions to bleed the system.

• Fill the reservoir
• Let it sit for 2 min
• lift the front end
• turn wheels lock to lock twice
• start the car
• turn wheels lock to lock twice
• lower vehicle

No joy.

Tonight, I reassembled the pump again, ensuring the tiny port for the pressure relief valve in the tail housing was clear.  I'll bleed it again tomorrow and report back.

I hope it isn't the power steering box.  That will be a major pain.

[Jeff Rosansky CLC #28373]

When you bled the system did the fluid level drop? I agree with cracking open the hi pressure line but also suggest the same with your return line. Having hi pressure is one thing, making all the way thru the system is another.
Jeff

[Tye_Cowan]

I couldn't see any bubbles, as I was in the driver's seat with no clear line of sight.

I'll Crack the return line and see what happens.

Thanks for the suggestions!

[Tye_Cowan]

Found another thread here with the same issue (No Power Assist after Pump Rebuild).

http://forums.cadillaclasalleclub.org/index.php?topic=102745.0

The last page indicates the solution to be an incorrectly sized "O" ring in the rebuild kit.  I don't understand why that would cause the problem, but am willing to put in the 90 minutes to give it a try.

Anyone with a solid technical explanation for why this "O" ring would cause a loss of pressure is invited to reply.

Tye Cowan

[Jeff Rosansky CLC #28373]

Depending on where the O ring is.
The pump may be sucking air if the O ring doesnt seal well.
Jeff

[Tye_Cowan]

Problem solved. It was the O-ring. I will be writing a letter of complaint to the manufacturer of the rebuild kit.

With the use of a pressure test unit that was built by a local shop I was able to determine the problem was actually in the pump. The results before and after where startling.

The first picture shows the car with the car running at idle developing no pressure at all. The second picture shows the car running at idle with the high pressure hose shut off developing almost 750 PSI. The third picture shows the difference in the sizes of the O-rings the thicker one being the one that came from the rebuild kit.

Videos can be viewed here:
Kit O-ring:  https://www.youtube.com/watch?v=uqR4194bhow
Original O-ring:  https://www.youtube.com/watch?v=BvuYKwyeoic
O-ring comparison:  https://www.youtube.com/watch?v=f7mwYDANaiY

[kav]

good to know ,when I do mine . thanks for the posts .

[Glen]

Do you have the part number of the correct O ring?  The number before the dash is the material it is made of and after the dash is the size, cross section and ID. 

[Tye_Cowan]

In short, no,  I do not have the part number to either the old one that works, or the offending new one. 

Cadillac Master Parts List says it is Cadillac Part Number 5664578 with no size description.  It goes around the Pressure Plate, and between the Ring Cam and Rear Cover.

The pump is manufactured with 2 O-rings inside.  Both have nearly identical cross sections, and differentiate only by inner and outer diameters.

The rebuild kit came with an O-ring that matched exactly to larger of the originals, and the 2nd had a larger cross section than the one it was to replace.

The two O-rings pictured above compare the original O-ring's cross section to that of the one found in the kit.

[PHIL WHYTE CLC 14192]

Hi Tye, I am glad you found my old post on this issue. I am also sorry to see that the kit manufacturer has not corrected this problem as this makes the kit useless. I have two 54 PS pumps and I rebuilt both and was lucky that the old seals were reusable. I am sorry I did not reply to your question on my old post as I very rarely come on this forum since I realised that a number of people on here were using it as a political platform!
Phil 

[D.Yaros]

I am sorry I did not reply to your question on my old post as I very rarely come on this forum since I realised that a number of people on here were using it as a political platform!
Phil

Phil, while I have missed your presence/participation I must have also missed the fact "that a number of people on here were using it as a political platform!"  That went right by me?

[Glen]

Whenever I am dealing with O-rings I use the guide below.  If you go to page 12 it gives dash numbers for the various size of O-rings.  It makes it easy for me to find the right O-ring for a given job.  The list is by cross section first, then inside diameter. 

I even have it on my cell phone.

[TJ Hopland]

So there is a vendor out there that has been selling the same wrong part for 8 years now?   And everyone who has bought the kit from them can now take apart and reassemble their pumps in their sleep because they had done and re done it so many times?   

[CadillacRob]

Who sold the rebuild kit?

[Tye_Cowan]

http://www.cadillacpartsltd.com/19capostpure.html

[CadillacRob]

Thats it.  They're on my shit list.

I bought a water pump rebuild kit from them thinking Id save some dough.  Kit comes, plastic bag reads "no returns if bag is opened".  Then I open it and read instructions only to find the new impeller needs to be machined down to fit in the water pump.  I immediately email asking them if I can return because I dont own a machine shop or lathe.  "No".   There goes $100  .   I told them they need to make the buyer AWARE of that on their website so others dont waste money.  "Thanks for the suggestion".   Website STILL doesnt say anything, and never will.

[kudims]

Had the same issue!!!

The thicker O-ring extrudes inside the chamber and does not let the pressure plate touch firmly the rotor wheel! And the pump does not produce any pressure.

One way is to find thinner O-ring (2mm), or to grind a bit the edge of the pressure plate, which can touch this o-ring. Both work

Bottom line: thicker O-ring after compression does not allow the pressure plate to stay in contact with the rotor assembly. Grind the outer diameter of the pressure plate to make it 1-1.5mm less in diameter, and it will work even with these thick o-rings.